Mill plate resharpening machine



Filed Aug. 23, 1938 3 Sheets-Sheet 1 HlHl I /Z7 I d 'gfase 072 ATTORNEYS Feb. 27, 1940.- .1. c. H. LEON MILL PLATE RESHARPENING' MACHINE Filed Aug. 2a. 1938 3 Sheets-Shoat 2 ATTORN EYS Patented Feb. 27, 1940 I UNITED STATES MILL PLATE RESHARPENING MACHINE Jose Leon, Tegucigalpa, Honduras Application August 23, 1938. Serial No. 226395 "Claims.

My invention relates to the treatment of mill plates and includes among its objects and advantages the provision of an improved mill plate resharpening machine. 7

An object .of my invention is to provide a device of the type described including a grinding wheel and a movable support for a mill plate to be resharpened and in which novel means are incorporated for turning the mill plate step by step together with novel means for advancing the mill plate towards the grinding stone to compensate wear on the latter.

A further object is to provide a device of the type described including a rotary grinding wheel arranged to be adjusted to different angles in.

which means are incorporated for bringing a mill plate into grinding relation with the stone and in which novel means are incorporated for turning the mill plate step by step as an incident to movement of the mill plate relatively to the I stone for grinding purposes. v

Another object is to provide a machine of the type described including a rotary grinding stone including novel reciprocatory means for manipulating a mill plate in grinding relation with the stone and in which ratchet mechanism is em- .ployed for automatically turning the mill plate to the next grinding-position upon completion of each succeeding grinding action.

With these and other objects in view, this invention consists in certain novel features of construction, combination and arrangement. of

parts to'be hereinafter more fully described and claimed.

For a complete understanding of my invention, reference is to be had to the following description and accompanying drawings, in which.

Figure 1 is an elevational view of a machine embodying my invention;

Figure 2 is a fragmentary view ofthe structure illustrated in Figure 1;

Figure 3 is a view'take'n from the position indicated by line 3-3 of Figure 2;

' Figure 4 is a sectional view along the line 4-4 of Figure 1;

Figure 5 is a sectional view along the line 5-5 of Figure 1;

Figure 6 is a detail'view of the ratchet mechanism; and I I Figure '7 is a diagrammatic face view of a mill plate which may be sharpened in the machine.

In the embodiment selected to illustrate my invention I make use of a base 10 including a flange ll of relatively large diameter for supporting the machine in an upright position on a floor or other support l2. If desirable the flange ll may be bolted to the supporting structure. Flange. II is cast intricately with the post l3 which is hollow and cast integrally with a hollow angular post l4. Within the post. I3 I fixedly 5 .connect one end of a tube l5 through the medium of a set screw l6. Tube [5 constitutes a support for the mill plate holder and actuater ll. Post l4 supports a tubular support l3 which includes an offset end l9 fixedly secured to the post [8 by a coupling element 20. Post l8 carries the grinding unit 2|.

Adjacent the upper end of the post I8 I mount a flange 22 which includes a collar 24 having threaded connection at 25 with the post l8. Upon the end of the post I8 I mount a base plate 26 having-a collar 21 rotatably related to the end of the post. Base plate 26 carries a fixed screw 28 projecting in the direction of the flange 22 andprovided with an'adjustable nut 29 which 0 may be brought into pressure relation with the flange 22 for restraining the base plate 26 from relative rotary movement. Upon the peripheral margin of the flange 261 provide graduation 30 while, the base plate 26 carries a fixed needle or 25 pointer 3| which is related to the graduation 30 to indicate angular adjustment of the base plate 26 about the axis of the tube l8.

On the base-plate 26 I mount a guide 32 and secure the guide in fixed position by bolt 33 pass-- 30 ing through the plate 26 and threaded into the guide. Guide 32 is grooved, as at 34, forslidably receiving the tongue 35 formed on the gear box 36. The transmission of the gear box is connected with a drive shaft 31 having a grooved; 35 pulley 38 for connection with a drive belt. The rotary grinding stone 39 "is operatively connected with the transmission in the gearbox. Since speed increasers of the gear type are well known in the art, the transmission need not be described 40 in further detail.

Projecting laterally of the base plate 26 is an arm 40 which may be cast intricately with the plate and the collar 21. Arm 4!! is provided with a threaded'opening 4| having threaded relation with an advancing screw 42 having its end 43 arranged in abutting relation with the gear box 36, see Figure 2. Gear box 36 may be adjusted in thedirection of the'mill plate unit [1 through rotation of the screw 42 which may be consum-. mated through the medium. of a handle 44 having pivotal connection at 45 with the screw. Screw 45 maybe secured against rotation through the medium of a screw 46 threaded into the end of the'iarm40. 'Adjustment of the gear box consequently the head 66.

36 toward the mill plate unit I! is consummated against the tension of a spring 47 havingone end anchored at 48 to the flange 49 carriedby the arm 40 and its opposite end anchored at 50 to the gear box. Rotation of the screw 42 in the opposite direction permits rearward movement of the gear box for moving the grinding stone 39 away from the mill plate unit because of the spring 47. For grinding purposes-the gear box unit is positively advanced through the medium of screw 42 and the screw constitutes an unyielding abutment for resisting the forces applied to the grinding stone 39.

Base plate 26 includes an upstanding flange 5! slotted at 52 for accommodation of a set screw 53 threaded into the gear box 36. The gear box includes a finger 54 which projects through the slot 52 and is readably related to graduation .55 on the outer face of the flange 5i along the slot 52 for indicating the advance position of the grinding stone 39. Flange t9 supportsa vertical bar 55 which carries the grinding stone dresser unit 5'l. Unit 51 may be adjusted longitudinally of the arm 56 through the medium of a fastening mount 58 extending through the slot 59 in the arm. Arm 56 carries a bolt 60 extending through a slot 6! in the flange 49; Boltfill is provided With wing nut 62 cooperable on the flange 49 for securing the arm 55 in position.

Inside the tube l5 I sli-dably mount .an innertube 63 which has its upper end threaded at 64 for connection with the neck 65 of the head 66. A suitable roller bearing assembly M is interposed between the upper end of the outer tube l5 and the innertube 63. Innertube 63 may be shifted inside the outer tube 15 for raising and lowering the head 66 but is restrained from relative rotary movement. In Figure l I illustrate a bracket 68 as having its lower end positioned in a-socket 69 in the base I0 and its upper end bolted at ll] to the outer tube l5. Bracket 68 is slotted at H for the reception of a lever 12 pivotally connected at 1'3 with the bracket 68. The inner end of. the lever 12 projects through a slot 14 in the outer tube [5 and its inner end extends through an opening 15in the innertube 63. It will thus be seen that the innertube 63 may be elevated through downward movement of the outer end of the lever 12. Opening 15 is of sufficient proportion to loosely receive the inner end of the lever, whileslot M is of sufficient length to accommodate the necessary shifting of the lever for elevating the inner-tubeand Figure 1 illustrates the inner tube 63 or the head 66 in its normal position.

Neck i55is hollow and communicates "with the hollow tubular part 16 of the head v56, see Figure 4. The mill plate to be resharpened isiindicated at T! and is detachably connected with a flange 18 through the medium of screws '19 extending through openings in the :mill plate and threaded into flange l8.

journaled at 82 in a closure plug 83 having threaded relation at 84 with the tubular part 16 -88 threaded into the end of the tubular part.

Plate '81 includes a boss #89 having a threaded [bearing 99 abutting the plate 3?.

Flange 18 is keyed "at '83 to a lead screw or shaft 8i having one end rotatably number of the channels iitl in the mill plateil.

Ratchet wheel $2 is rotated one tooth at a time for turning the mill piate l! a corresponding distance for bringing the next grinding position into grinding relation with the grinding wheel 39. Rotation of the ratchet Wheel 92 one tooth at a time imparts slight axial movement to the lead screw or shaft for advancing the mill plate H a corresponding distance in the direction of the grinding wheel 39 to compensate wear of the latter.-

Adjacent the inner face of the plug 831 mount 5 a friction disk 95 which is held in pressure relation with the closure plate through the medium of a washer 96 keyed at ill to the shaft ill and urged against the friction disk through the mediurn of acompression spring diihaving one end 7 arranged in pressure relation with the washer 9t and its opposite end lying against thrust It will thus be seen that the shaft iltwhile rotatably mounted is restrained from accidental rotary movement I because of the breaking action of the friction diet:

35 which bears against the plug keyed to the flange l8;

Keyed connection 9'! permits relative longitudinal movement of the shaft 8! with respect to the Washer 86.

Upon the reduced extension mil projecting beyond the ratchet WheelQZ and comprising apart of the shaft 8| Imount a pall actuatinglever Hll.

Lever l0! rotates freely on the shaft part Hill and is bent to providea parallel reach H12 which supports one end of a pin Sill-l having its other end 1 supported -by the lever 18!. Aspawl 184 is ,pivv otally mounted on the pin l 13 and is yieldingly urged into pressure relation with the ratchet wheel92 by aspring we having one-endfixedly connected at Hi6 with thecross reach Ill! interconnecting the reach Hi2 with the lever ml Pawl I04 is shifted through the medium of the lever lOl sufficiently far to be brought into abut ting relation with the next tooth on the Wheel 62 for rotating the wheel upon pivotal movement of the lever Nil in the opposite direction.

Figure a illustrates the opposite endfof the lever HHv as being bent to extend across the face- 1 of the ratchet wheel 92 and inwardly of its opposite side, as at I03. [The lever is further bent at [09 to ,provide an arm Hi3 which parallels the tubular part 16. To the outer tube [5 I connect a bracket ill through the medium of bolts H2. The vertical run of the bracket comprises a shaft threaded at I I3 for the reception of lock nuts i it constituting a stop or rest for the arm H0. Figarm ill) andthe stop- 114. I anchor a companion stop H5 to the plate 81 slightly under.- neath the upper face of-the stop H6. Stop H5 may comprise a bolt threaded into the plate 8T.

A-tension spring Hfihas one end secured at i l'!- to the arm H0 and its opposite end secured at H8 to thexboss 89. Raising of the head '66 lifts the arm HG off the rest 5M while atthe same time the spring l IE will pull arm 5 l0 downwardly for moving the far end of the lever llll upwardlysufl'iciently far to bring the pall I04 into engageure 1 illustrates the normal relation 'between'th'e ment with the next tooth onthe ratchet wheel 92. I 1

The stop H5 is spaced beneath the supporting face not-the stop l vsuiiiciently far to permit all the necessary pivotal movement of the lever IOI, but acts to prevent further pivotal movement after the pawl I04 has been shifted into latching relation with the'next tooth. Upon lowering of the head 66 the arm IIO will'be brought into engagement with the stop H4 after which further lowering of the head causes the lever IOI to pivot in the opposite direction thereby rotating the ratchet wheel 92 in the direction of the arrow II9 of Figure 6 a distance equal to the space between two teeth. Lock nuts constituting the stop II I may be adjusted on the bracket III to secure precise adjustment for the arm I I0.

Within the innertube 63 I mount a tension spring I2I one end of which terminates in a wire I22 fastened to the shaft or lead screw 8|, as

at I23 in Figure 4. The opposite end of the spring I2I terminates in a wire I24 which is connected with an eye I25 secured to a support I26 made secure inside the base I0 by a set screw I2'I. Spring I2I operates to exert a downward pull on'the hinge 66. Elevation of the head extends the spring I2I so that its increased tension is effective on the head for lowering purposes although the head tends to drop by gravity alone in the absence of lifting forces on the lever I2.

Outer tube I5 is provided with diametrically opposed longitudinal slots I28 within which slide blocks or keys I29 are positioned. Keys I29 include projections I30 which ride in slots I3I in the innertube 63. Extensions I30 restrain the innertube 63 from relative rotary movement but permit free longitudinal movement with respect to the outer guide tube I5. The outer guide tube I5 may be provided with a stop I32 arranged to I engage one of the slots I29 for limiting the upward position of the head 66. Stop I32 is adjustable through the medium of a screw I33 which is also true of the block I29 because of the screw I34.

Within the post I3 I mount a cushioning spring I35. One end of the spring rests on the support I 26 while its opposite end embraces the lower end of the innertube 63 and abuts a cross pin I36 passing to the innertube. Spring I35 functions as a cushioning means for the head as it is lowered, but the weight of the head together with the pulling force of the spring I2I is more than sufiicient to overcome lifting tendencies of the spring I35.

From the foregoing description of the various parts of the device the operation thereof will be readily understood. The grinding stone 39 may be adjusted for'angularity through rotation of the'base plate 26 about the axis of the vertical reach of the post I8. Pointer 3| indicates the degree of angularity while adjustment of the nut 29 secures the base plate 26 in the position of selected angularity. The forward'position of the grinding stone 39 is determined through the medium of the screw 42 which moves the gear box 36 bodily relatively to the guide 32. The

forward or grinding position of the stone 39 is indicated by the pointer 54 while tightening of the screw 53 secures the gear box in fixed relation to the guide 32. Pointer 54 may comprise: a separable part secured to the gear box 36.by a

. screw I36.

Figure 7 illustrates the channels 94 as being arranged tangentially of the mill plate I! but the horizontal center line of the stone 39. After the 'grindingstone 39 has been adjusted to the proper cutting position with respect to the mill plate TI, the lever I2 is pivoted downwardly which elevates the head 66 and moves the mill plate TI across the face of the grinding stone 39. The channels 94 terminate considerably short of the central axis of the mill plate so that the movement of the mill plate across the grinding face of the stone may be considerably less than the diameter of the mill plate.

Immediately upon lifting of the head 53 the arm II 0 moves downwardly because of the tension of the spring IIIi until the arm comes to rest on the stop II5. Stop H5 limits further pivotal action of the pall lever IBI as the head 66 continues its upward movement but the pivotal action of the lever IOI is sufficient to shift the pall I09 into engagement with the next tooth abutting relation with the stop IM. As the arm I I engages the stop I I4 further downward movement of the head 90 rotates the ratchet wheel 92 a slight distance for advancing the mill plate TI towards the grinding stone 39 thereby compensating wear of the latter.

Teeth 93 on the peripheral face of the ratchet wheel. 92 are spaced so that the pall {04 will rotate the mill plate I'I one channel at a time for presentation to the grinding face of the stone 39. The entire face of the mill plate Il may be resharpened through manipulation of the lever I2. The friction disk 95 which is cooperable on the washer 96 keyed to the shaft 0! restrains the shaft from accidental rotary move- 1. A device for resharpening channeled mill plates comprising a grinding means, a guide, a standard slidably related to the guide for movement in a reciprocatory path, a head carried by said standard, a mill plate mount including a shaft rotatably journaled in said head, a screw connection between the shaft and the head, a ratchet wheel fixedly connected with said shaft, said ratchet wheel having teeth corresponding in number to the channels in the mill plate, and pall means including an operable connection with said guide for rotating the shaft to advance the mill plate to successive grinding position. as the head is reciprocated, said screw connection operating to advance the mill plate mount towards the grinding stone, to compensate wear of the latter. r

2. A device of the type described comprising a grinding stone, a work mount, a support, a shaft keyed to the work mount and threadedly related to said support for rotation therein, a relatively fixed guide, a companion guide fixed to said support and slidably related to said fixed guide, means for actuating said companion guide to shift the support and said work mount for presenting the work to the grinding stone, and an operating connection between said relatively fixed guide and said shaft for turning the latter to shift the work mount for advancing the work to successive grinding positions with respect to said grinding stone and for advancing the work mount toward the grinding stone, to compensate for wear of the latter.

3. A device of the type described comprising a grinding stone, a work mount, a support, a shaft keyed to the work mount and threadedly related to said support for rotation therein, a relatively fixed, vertical guide, a companion guide fixed to said support and slidable vertically of said fixed guide, said work mount normally being positioned beneath said grinding stone, means for elevating said companion guide to lift the support and said work mount for presenting the work to the grinding stone, and an operating connection between said relatively fixed, vertical guide and said shaft for turning the latter to shift the work mount for advancing the work to successive grinding positions with respect to said grinding stone and for advancing the work mount toward the grinding stone, to compensate for wear of the latter.

4. A device of the type described comprising a grinding stone, a work mount, a support, a shaft keyed to the work mount and threadedly related to said support for rotation therein, a relatively fixed, vertical guide, a companion guide fixed to said support and slidably related to said relatively fixed, vertical guide, means for elevating said companion guide to shift the support and said work mount for presenting the work to the grinding stone, and an operating connection between said relatively fixed, vertical guide and said shaft for turning the latterto shift the work mount for advancing the work to successive grinding positions with respect tosaid grinding stone as said support and the work mount approach their normal positions beneath the grinding stone, said shaft being shifted axially when rotated for advancing the work mount toward the grinding stone, to compensate for wear of the latter.

5. A device of the type described comprising a' grinding stone, a work mount, a support, a shaft keyed to the work mount and threadedly related to said support for rotation therein, a relatively fixed, vertical guide, a companion. guide fixed to said support and slidably related to said fixed neath the grinding stone, rotation of said shaft advancing the work mount toward the grinding stone, to compensate for wear of the latter, and resilient means cooperable with said relatively fixed, vertical guide and said shaft for urging the support and the work mount to their normal positions beneathsaid grinding stone.

JosE c. H. LEON.

1. guide, means for elevating said companion guide to shift the work support and said "work mount 

